Sample size was calculated for each pharmacy using Epidat 4.0 based on a population of 350 patients arriving to the pharmacy weekly, assuming that 50% of the population self- medicates, a precision of 5% and a 95% confidence level. Customers who purchased antibiotics without a prescription were invited to participate in the study. Written informed consent was obtained and participants were given a brief verbal definition of the practice of self-medication and the opportunity to ask any questions regarding the study or self- medication with antibiotics. Participants were asked to complete the questionnaire, which consisted of a brief introduction of study objectives and a definition of self-medication: “Self- medication occurs when patients obtain and use medications without a prescription from a doctor, meaning that patients make a personal decision to seek treatment for their illness.” We determined which antibiotics were being used for self-medication by documenting the generic name of the antibiotic at the time the participant purchased the medication